A groups of aliens known only as the Mysterious Invaders are an alien race who appear with powerful living weapons to destroy humanity and take control of Earth for unknown reasons in a series of verses films and their related media. While they are never given an official name, the Mysterious Invaders are given the name the Damdom and are the arch rivals of the Vegan Empire in Dynamic Heroes. Later iterations would use the Damdom name for simplicity's sake.
Great Mazinger vs. Getter Robo[]
In Great vs. Getter a mysterious ship sends an egg onto Earth that later hatches into Gilgilgan. When the beast was cornered by Great Mazinger and Getter Robo in its second form, the ship sacrifices itself to Gilgilgan allowing it to morph into its final form.
Great Mazinger vs. Getter Robo G: Kuchu Daigekitotsu[]
With Gilgilgan destroyed, another group of Invaders send in three monsters: Grangen, Bong, and Pikadron to attack Earth.
Grendizer vs Steel Jeeg[]
In the short story based off of the unproduced final installment of the Versus series of movies, the Damdom lead one final assault on Planet Earth with the few remaining monsters they have. With the combined efforts of Grendizer, Steel Jeeg and the Getter Robo G team, the last of Damdom's monsters are eliminated. As the Damdom leaders tried fleeing back into space, the 3 pilots of Getter Dragon ultimately destroy their mothership in a single blow to avenge the death of Musashi who had been killed by the Grangen in the previous movie. With their entire fleet destroyed once and for all, the Damdom invaders had ironically been driven into extinction by the very race of 'lesser' aliens whom they tried and tried to wipe out twice before.
Mazinkaiser vs. Shin Getter Robo[]
The Damdom release their mass produced Pikadron robots upon Tokyo which the Mazinger robots were no match for and had already decimated the Getter Robo. Later they unleashed another beast named Gilgilgan when the Shin Getter Robo was unleashed. The appearance of Mazinkaiser however forces them to change Gilgilgan into a mechanized form and sprout eggs to make more Gilgilgans. Fortunately, both robots managed to destroy Mecha Gilgilgan and Boss Borot destroyed the Damdom ship before it could give the signal to hatch the eggs.
Dynamic Heroes[]
In Dynamic Heroes, The Dandom serve as the primary antagonists, rebuilding some of their destroyed monsters like Gilgilgan to destroy the Earth once and for all. However, with the combined effort of a heroic Armada lead by the Mazinger trio, Getter Robo G, Devilman and Cutey Honey, the Dandom are finally wiped out once and for all. This manga not only solidified the name for the empire as Dandom, but also established that they had a prior war with the Vegan Empire.
Robot Girls Z+[]
In Robot Girls Z+, the main antagonist Gilgilganko is revealed to be a member of the Damdom and even controls fleets of UFOs.